#include <stdio.h>
int a,k;
int calcAge(int n)
{
    if(n==1) return a;
    return calcAge(n-1)+k;
}

int main()
{
    int n=1;
    printf("please input:\n");
    scanf("%d",&n);
    printf("the age is%d\n",calcAge(n));
    
	
	return 0;
}
